Download Physical Features of India

is
he
The movement of the plates results in the
building up of stresses within the plates and the
continental rocks above, leading to folding,
faulting and volcanic activity. Broadly, these
plate movements are classified into three
types(Figure 2.1). While some plates come towards
each other and form convergent boundary. Some
plates move away from each other and form
divergent boundary. In the event of two plates
coming together they may either collide and
crumble, or one may slide under the other. At
times, they may also move horizontally past
©
no N
C
tt E
o R
be T
re
pu
bl
Y
ou have already learnt earlier that India
is a vast country with varied landforms.
What kind of terrain do you live in? If
you live in the plains you are familiar with the
vast stretches of plain land. In contrast, if you
live in hilly region, the rugged terrain with
mountains and valleys are common features.
In fact, our country has practically all major
physical features of the earth i.e. mountains,
plains, deserts, plateaus and islands. You
must be wondering how these physical
features have been formed. We will learn more
about major physical features of India and how
they have been formed.
We find different types of rocks; some are
very hard like marble which has been used for
making the Taj Mahal, and some are very soft
like soap stone which is used in making talcum
powder. The colour of soil varies from one place
to the other because soil is formed out of
different types of rocks. Have you ever thought
about the causes of these variations? Most of
these variations are caused due to differences
in rock formations.
India is a large landmass formed during
different geological periods which has influenced
her relief. Besides geological formations, a
number of processes such as weathering,
erosion and deposition have created and
modified the relief to its present form.
Earth scientists have attempted to explain
the formation of physical features with the help
of some theories based on certain evidences.
One such plausible theory is the “Theory of Plate
Tectonics”. According to this theory, the crust
(upper part) of the earth has been formed out of
seven major and some minor plates. (Figure 2.2)
INDIA
OF
d
PHYSICAL F EATURES
2
PLATE
PLATE
Mantle
Convergent Boundary
PLATE
Divergent Boundary
PLATE
Mantle
PLATE
Mantle
PLATE
Mantle
Transform Boundary
Figure 2.1 : Plate Boundaries
d
he
is
bl
©
no N
C
tt E
o R
be T
re
pu
Figure 2.2 : World : Plate Margins
each other and form transform boundary. The
movement of these plates have changed the
position and size of the continents over millions
of years. Such movements have also influenced
the evolution of the present landform features
of India.
Most
volcanoes
and
earthquakes in the world are located at plate
margins, but some do occur within the plates.
The oldest landmass, (the Peninsula part), was
a part of the Gondwana land. The Gondwana
land included India, Australia, South Africa,
South America and Antarctica as one single land
mass. The convectional currents split the crust
into a number of pieces, thus leading to the drifting
of the Indo-Australian plate after being separated
from the Gondwana land, towards north. The
northward drift resulted in the collision of the plate
with the much larger Eurasian Plate. Due to this
collision, the sedimentary rocks which were
accumulated in the geosyncline known as the
Tethys were folded to form the mountain system
of western Asia and Himalaya.
8
Gondwana land: It is the southern part of the
ancient super continent Pangea with Angara Land
in the northern part.
The Himalayan uplift out of the Tethys sea
and subsidence of the northern flank of the
peninsular plateau resulted in the formation
of a large basin. In due course of time this
depression, gradually got filled with deposition
of sediments by the rivers flowing from the
mountains in the north and the peninsular
plateau in the south. A flat land of extensive
alluvial deposits led to the formation of the
northern plains of India.
The land of India displays great physical
variation. Geologically, the Peninsular Plateau
constitutes one of the ancient landmasses on
the earth’s surface. It was supposed to be one
of the most stable land blocks. The Himalayas
and the Northern Plains are the most recent
landforms. From the view point of geology,
Himalayan mountains form an unstable zone.
The whole mountain system of Himalaya
represents a very youthful topography with
high peaks, deep valleys and fast flowing rivers.
The northern plains are formed of alluvial
CONTEMPORARY INDIA
The Himalayan Mountains
©
no N
C
tt E
o R
be T
re
pu
bl
The Himalayas, geologically young and
structurally fold mountains stretch over the
d
The physical features of India can be grouped
under the following physiographic divisions
(Figure 2.4):
(1) The Himalayan Mountains
(2) The Northern Plains
(3) The Peninsular Plateau
(4) The Indian Desert
(5) The Coastal Plains
(6) The Islands
he
MAJOR PHYSIOGRAPHIC D IVISIONS
northern borders of India. These mountain
ranges run in a west-east direction from the
Indus to the Brahmaputra. The Himalayas
represent the loftiest and one of the most
rugged mountain barriers of the world. They
form an arc, which covers a distance of about
2,400 Km. Their width varies from 400 Km
in Kashmir to 150 Km in Arunachal Pradesh.
The altitudinal variations are greater in the
eastern half than those in the western half.
The Himalaya consists of three parallel
ranges in its longitudinal extent. A number
of valleys lie between these ranges. The
northern most range is known as the Great
or Inner Himalayas or the ‘Himadri’. It is the
most continuous range consisting of the
loftiest peaks with an average height of 6,000
metres. It contains all the prominent
Himalayan peaks.
is
deposits. The peninsular plateau is composed
of igneous and metamorphic rocks with gently
rising hills and wide valleys.
Figure 2.3 : Himalayas
PHYSICAL FEATURES OF INDIA
9
d
he
is
bl
©
no N
C
tt E
o R
be T
re
pu
Figure 2.4 : Relief
10
CONTEMPORARY INDIA
Nepal
India
Nepal
Nepal
India
Nepal
India
India
India
Nepal
8848
8598
8481
8172
8126
8078
7817
7756
7756
7728
The folds of Great Himalayas are
asymmetrical in nature. The core of this part
of Himalayas is composed of granite. It is
perennially snow bound, and a number of
glaciers descend from this range.
• The names of the glaciers and passes
that lie in Great Himalayas
• The name of the states where highest peaks
are located.
Figure 2.5 : The Himalayas
Besides the longitudinal divisions, the
Himalayas have been divided on the basis of
regions from west to east. These divisions
have been demarcated by river valleys. For
example, the part of Himalayas lying between
Indus and Satluj has been traditionally
known as Punjab Himalaya but it is also
known regionally as Kashmir and Himachal
Himalaya from west to east respectively. The
part of the Himalayas lying between Satluj
and Kali rivers is known as Kumaon
Himalayas. The Kali and Tista rivers
demarcate the Nepal Himalayas and the part
lying between Tista and Dihang rivers is
known as Assam Himalayas. There are
regional names also in these broad
categories. Find out some regional names of
the Himalayas
The Brahmaputra marks the eastern most
boundary of the Himalayas. Beyond the Dihang
gorge, the Himalayas bend sharply to the south
and spread along the eastern boundary of
India. They are known as the Purvachal or the
Eastern hills and mountains. These hills
running through the north-eastern states are
mostly composed of strong sandstones which
are sedimentary rocks. Covered with dense
forests, they mostly run as parallel ranges
and valleys. The Purvachal comprises the
©
no N
C
tt E
o R
be T
re
pu
The range lying to the south of the Himadri
forms the most rugged mountain system and
is known as Himachal or lesser Himalaya. The
ranges are mainly composed of highly
compressed and altered rocks. The altitude
varies between 3,700 and 4,500 metres and
the average width is of 50 Km. While the Pir
Panjal range forms the longest and the most
important range, the Dhaula Dhar and the
Mahabharat ranges are also prominent ones.
This range consists of the famous valley of
Kashmir, the Kangra and Kullu Valley in
Himachal Pradesh. This region is well known
for its hill stations.
d
Mt. Everest
Kanchenjunga
Makalu
Dhaulagiri
Nanga Parbat
Annapurna
Nanda Devi
Kamet
Namcha Barwa
Gurla Mandhata
Height
in metres
he
Country
is
Peak
alluvium. The longitudinal valley lying
between lesser Himalaya and the Shiwaliks are
known as Duns. Dehra Dun, Kotli Dun and
Patli Dun are some of the well-known Duns.
bl
Some Highest Peaks of the Himalayas
• Location of Mussoorie, Nainital,
Ranikhet from your atlas and also name the state
where they are located.
The outer most range of the Himalayas is
called the Shiwaliks. They extend over a width
of 10-50 Km and have an altitude varying
between 900 and 1100 metres. These ranges
are composed of unconsolidated sediments
brought down by rivers from the main
Himalayan ranges located farther north. These
valleys are covered with thick gravel and
PHYSICAL FEATURES OF INDIA
11
Majuli, in the Brahmaputra
River is the largest inhabited riverine island in the
world.
d
‘Doab’ is made up of two
words- ‘do’ meaning two and ‘ab’ meaning water.
Similarly ‘Punjab’ is also made up two words- ‘Punj’
meaning five and ‘ab’ meaning water.
The Ganga plain extends between Ghaggar
and Teesta rivers. It is spread over the states of
North India, Haryana, Delhi, U.P., Bihar, partly
Jharkhand and West Bengal to its East,
particularly in Assam lies the Brahmaputra plain.
The northern plains are generally deseribed
as flat land with no variations in its relief. It is
not true. These vast plains also have diverse
relief features. According to the variations in
relief features, the Northern plains can be
divided into four regions. The rivers, after
descending from the mountains deposit
pebbles in a narrow belt of about 8 to 16 km
in width lying parallel to the slopes of the
Shiwaliks. It is known as bhabar. All the
streams disappear in this bhabar belt. South
of this belt, the streams and rivers re-emerge
and create a wet, swampy and marshy region
known as terai. This was a thickly forested
region full of wildlife. The forests have been
cleared to create agricultural land and to settle
migrants from Pakistan after partition. Locate
Dudhwa National Park in this region.
The largest part of the northern plain is
formed of older alluvium. They lie above the
flood plains of the rivers and present a terrace
like feature. This part is known as bhangar.
©
no N
C
tt E
o R
be T
re
pu
The northern plain has been formed by the
interplay of the three major river systems,
namely– the Indus, the Ganga and the
Brahmaputra along with their tributaries. This
plain is formed of alluvial soil. The deposition
of alluvium in a vast basin lying at the foothills
of the Himalaya over millions of years, formed
this fertile plain. It spreads over an area of 7
lakh sq. km. The plain being about 2400 Km
long and 240 to 320 Km broad, is a densely
populated physiographic division. With a rich
soil cover combined with adequate water
supply and favourable climate it is
agriculturally a very productive part of India.
he
The Northern Plain
is
Patkai hills, the Naga hills, Manipur hills and
the Mizo hills.
bl
Figure 2.6 : Mizo Hills
The rivers in their lower course split into
numerous channels due to the deposition of silt.
These channels are known as distributaries.
The Northern Plain is broadly divided into
three sections. The Western part of the Northern
Plain is referred to as the Punjab Plains.
Formed by the Indus and its tributaries, the
larger part of this plain lies in Pakistan. The
Indus and its tributaries–the Jhelum, the
Chenab, the Ravi, the Beas and the Satluj
originate in the Himalaya. This section of the
plain is dominated by the doabs.
Figure 2.7 : The Northern Plains
The rivers coming from northern
mountains are involved in depositional work.
In the lower course, due to gentle slope, the
velocity of the river decreases which results in
the formation of riverine islands.
12
CONTEMPORARY INDIA
d
he
©
no N
C
tt E
o R
be T
re
pu
The Peninsular plateau is a tableland
composed of the old crystalline, igneous and
metamorphic rocks. It was formed due to the
breaking and drifting of the Gondwana land
and thus, making it a part of the oldest
landmass. The plateau has broad and shallow
valleys and rounded hills. This plateau
consists of two broad divisions, namely, the
Central Highlands and the Deccan Plateau.
The part of the Peninsular plateau lying to
the north of the Narmada river covering a
major area of the Malwa plateau is known as
the Central Highlands. The Vindhyan range
is bounded by the Central Highlands on the
south and the Aravalis on the northwest. The
further westward extension gradually merges
with the sandy and rocky desert of Rajasthan.
The flow of the rivers draining this region,
namely the Chambal, the Sind, the Betwa and
Ken is from southwest to northeast, thus
indicating the slope. The Central Highlands
are wider in the west but narrower in the east.
The eastward extensions of this plateau are
locally known as the Bundelkhand and
Baghelkhand. The Chotanagpur plateau
marks the further eastward extension,
drained by the Damodar river.
is
The Peninsular Plateau
The Deccan Plateau is a triangular landmass
that lies to the south of the river Narmada. The
Satpura range flanks its broad base in the north
while the Mahadev, the Kaimur hills and the
Maikal range form its eastern extensions. Locate
these hills and ranges in the physical map of
India. The Deccan Plateau is higher in the west
and slopes gently eastwards. An extension of the
Plateau is also visible in the northeast– locally
known as the Meghalaya, Karbi-Anglong Plateau
and North Cachar Hills. It is separated by a
fault from the Chotanagpur Plateau. Three
Prominent hill ranges from the west to east are
the Garo, the Khasi and the Jaintia Hills.
The Western Ghats and the Eastern Ghats
mark the western and the eastern edges of the
Deccan Plateau respectively. Western Ghats lie
parallel to the western coast. They are continuous
and can be crossed through passes only. Locate
the Thal, Bhor and the Pal Ghats in the Physical
map of India.
The Western Ghats are higher than the
Eastern Ghats. Their average elevation is 900–
1600 metres as against 600 metres of the
Eastern Ghats. The Eastern Ghats stretch from
the Mahanadi Valley to the Nigiris in the south.
The Eastern Ghats are discontinuous and
irregular and dissected by rivers draining into
the Bay of Bengal. The Western Ghats cause
orographic rain by facing the rain bearing moist
winds to rise along the western slopes of the
Ghats. The Western Ghats are known by
different local names. The height of the Western
Ghats progressively increases from north to
south. The highest peaks include the Anai
Mudi (2,695metres) and the Doda Betta (2,637
metres). Mahendragiri (1,501 metres) is the
highest peak in the Eastern Ghats. Shevroy
Hills and the Javadi Hills are located to the
southeast of the Eastern Ghats. Locate the
famous hill stations of Udagamandalam,
popularly known as Ooty and the Kodaikanal.
One of the distinct features of the peninsular
plateau is the black soil area known as Decean
Trap. This is of volcanic origin hence the rocks
are igneous. Actually these rocks have
denuded over time and are responsible for the
formation of black soil. The Aravali Hills lie on
the western and northwestern margins of the
bl
The soil in this region contains calcareous
deposits locally known as kankar. The newer,
younger deposits of the flood plains are called
khadar. They are renewed almost every year
and so are fertile, thus, ideal for intensive
agriculture.
Figure 2.8 : A waterfall in Chotanagpur Plateau
PHYSICAL FEATURES OF INDIA
13
peninsular plateau. These are highly eroded
hills and are found as broken hills. They extend
from Gujarat to Delhi in a southwest-northeast
direction.
he
Figure 2.10 : The Coastal Plains
The plains along the Bay of Bengal are wide
and level. In the northern part, it is referred to
as the Northern Circar, while the southern part
is known as the Coromandel Coast. Large
rivers such as the Mahanadi, the Godavari, the
Krishna and the Kaveri have formed extensive
delta on this coast. Lake Chilika is an
important feature along the eastern coast.
©
no N
C
tt E
o R
be T
re
pu
bl
is
The Indian desest lies towards the western
margins of the Aravali Hills. It is an undulating
sandy plain covered with sand dunes. This
region receives very low rainfall below 150 mm
per year. It has arid climate with low
vegetation cover. Streams appear during the
rainy season. Soon after they disappear into
the sand as they do not have enough water to
reach the sea. Luni is the only large river in
this region.
d
The Indian Desert
The Chilika Lake is the
largest salt water lake in India. It lies in the state
of Orissa, to the south of the Mahanadi delta.
The Islands
Figure 2.9 : The Indian Desert
Barchans (crescent shaped dunes) cover
larger areas but longitudinal dunes become
more prominent near the Indo-Pakistan
boundary. If you visit Jaisalmer, you may go
to see a group of barchans.
You have already seen that India has a vast main
land. Besides this, the country has also two groups
of islands. Can you identify these island groups?
The Coastal Plains
The Peninsular plateau is flanked by stretch
of narrow coastal strips, running along the
Arabian Sea on the west and the Bay of Bengal
on the east. The western coast, sandwiched
between the Western Ghats and the Arabian
Sea, is a narrow plain. It consists of three
sections. The northern part of the coast is called
the Konkan (Mumbai – Goa), the central stretch
is called the Kannad Plain while the southern
stretch is referred to as the Malabar coast.
14
Figure 2.11 : An Island
Locate the Lakshadweep Islands group
lying close to the Malabar coast of Kerala. This
group of islands is composed of small coral
isalnds. Earlier they were known as Laccadive,
Minicoy and Amindive. In 1973 these were
CONTEMPORARY INDIA
named as Lakshadweep. It covers small area
of 32 sq km. Kavaratti island is the
administrative headquarters of Lakshadweep.
This island group has great diversity of flora
and fauna. The Pitti island, which is
uninhabited, has a bird sanctuary.
starategic importance for the country. There
is great diversity of flora and fauna in this
group of islands too. These islands lie close to
equator and experience equatorial climate and
has thick forest cover.
India’s only active volcano is
found on Barren island in Andaman and Nicobar
group of Islands.
Corals
d
Coral polyps are short-lived microscopic
organisms, which live in colonies. They flourish
in shallow, mud free and warm waters. They
secrete calcium carbonate. The coral secretion
and their skeletons from coral deposits in the
form of reefs:. they are mainly of three kinds:
barrier reef. fringing reef and atolls. The Great
Barrier Reef of Australia is a good example of the
first kind of coral reefs. Atolls are circular or
horse shoe shaped coral reefs.
bl
©
no N
C
tt E
o R
be T
re
pu
Now you see the elongated chain of islands
located in the Bay of Bengal extending from
north to south. These are Andaman and
Nicobar islands. They are bigger in size and
are more numerous and scattered. The entire
group of islands is divided into two broad
categories – The Andaman in the north and
the Nicobar in the south. It is believed that these
islands are an elevated portion of submarine
mountains. These island groups are of great
is
he
A detailed account of the different
physiographic units highlights the unique
features of each region. It would, however,
be clear that each region complements the
other and makes the country richer in its
natural resources. The mountains are the
major sources of water and forest wealth.
The northern plains are the granaries of the
country. They provide the base for early
civilisations. The plateau is a storehouse
of minerals, which has played a crucial role
in the industrialisation of the country. The
coastal region and island groups provide
sites for fishing and port activities. Thus,
the diverse physical features of the land
have immense future possibilities of
development.
EXERCISE
1. Choose the right answer from the four alternatives given below.
(i) A landmass bounded by sea on three sides is referred to as
(a) Coast
(c) Peninsula
(b) Island
(d) none of the above
(ii) Mountain ranges in the eastern part of India forming its boundary with
Myanmar are collectively called as
(a) Himachal
(c) Purvachal
(b) Uttarakhand
(d) none of the above
(iii) The western coastal strip, south of Goa is referred to as
(a) Coromandel
(c) Kannad
(b) Konkan
(d) Northern Circar
(iv) The highest peak in the Eastern Ghats is
(a) Anai Mudi
(c) Mahendragiri
(b) Kanchenjunga
(d) Khasi
2 Answer the following questions briefly.
(i) What are tectonic plates?
(ii) Which continents of today were part of the Gondwana land?
PHYSICAL FEATURES OF INDIA
15
d
6.
7.
he
4.
5.
MAP SKILLS
is
3.
(iii) What is the bhabar?
(iv) Name the three major divisions of the Himalayas from north to south.
(v) Which plateau lies between the Aravali and the Vindhyan ranges?
(vi) Name the island group of India having coral origin.
Distinguish between
(i) Converging and diverging tectonic plates
(ii) Bhangar and Khadar
(iii) Western Ghats and Eastern Ghats
Describe how the Himalayas were formed.
Which are the major physiographic divisions of India? Contrast the relief of the
Himalayan region with that of the Peninsular plateau.
Give an account of the Northern Plains of India.
Write short notes on the following.
(i) The Indian Desert
(ii) The Central Highlands
(iii) The Island groups of India
©
no N
C
tt E
o R
be T
re
pu
bl
On an outline map of India show the following.
(i) Mountain and hill ranges – the Karakoram, the Zaskar, the Patkai Bum, the
Jaintia, the Vindhya range, the Aravali, and the Cardamom hills.
(ii) Peaks – K2, Kanchenjunga, Nanga Parbat and the Anai Mudi.
(iii) Plateaus, Chotanagpur and Malwa
(iv) The Indian Desert, Western Ghats, Lakshadweep Islands
PROJECT/ACTIVITY
Locate the peaks, passes, ranges, plateaus, hills, and duns hidden in the puzzle.
Try to find where these features are located. You may start your search horizontally,
vertically or diagonally.
16
CONTEMPORARY INDIA